The present invention relates to a pivot pin assembly for pivotally mounting two highly loaded parts together, and which has an arm or lever that can be secured to one of the parts carrying the pin to prevent rotation of the pin as a second part, also mounted on the pin, rotates relative to the first part. In particular, the pivot pin assembly has a shoulder, forming a non-circular boss on one end and a retainer lever is provided with a bore fitting over the boss. A cap screw is screwed into the end of the pin and used to retain the lever on the boss.
In the prior art, pivot pins used in high load pivots, such as the pivot pin securing an accessory attachment plate to the front end of loader arms, are secured to prevent pin rotation when the two parts pivot. One form of pin retainer is to provide a cross bore through a support hub and the pin at one end, and inserting spring pin or a cotter pin to secure the pivot pin to the hub that surrounds the pivot pin.
In another type of pivot pin, a lever or plate is welded to the pin end and the lever is secured to a surface of one of the pivoting parts. This type of pin is widely used, but requires purchasing a heat treated pin, welding the lever or retainer plate on the pin, and then sending the weldment out for plating and/or further heat treatment after welding.
Other types of securable pivot pins also are available, such as pins that have irregular shaped pin heads that will fit into a receptacle.
The present invention relates to a pivot pin used to pivotally mount two parts together, such as a bucket or accessory mounting plate at the ends of loader arms. The pivot pin has a radially extending lever or retainer plate at one end of the pin that is secured to one of the parts to prevent the pin from rotating. The accessory mounting plate on a loader is tiltable on the pivot pins when underload, using a hydraulic cylinder. The pivot pins may tend to rotate unless restrained.
The pins of the present invention are circular cross section cylinders having a central axis, which forms a pivot axis of the two parts that are held by the pin. An end of the pin has a surface that is at least partially at right angles to the central axis. A shoulder is formed at the one end so that the end surface is stepped or has a xe2x80x9cbossxe2x80x9d. The shoulder has a surface portion that is non-circular, to form a stop surface. A lever or plate has a bore or receptacle that receives the boss, and the lever bore has an inner edge surface that mates with the shoulder so the lever will not rotate about the pin axis. When the outer end of the lever is restrained by fixing it to one of the parts that is pivoted together, the lever will resist the torque that tends to rotate the pin.
The pin assembly of the present invention provides a great advantage in manufacturing. A hardened pin can have an end machined easily to the desired boss shape, and a lever opening can be punched to receive the boss at the end of the pin. The lever is held onto the pin end with a bolt and washer, or a flanged head bolt, that has a surface of size to bear on the lever to hold the lever onto the boss. The lever or arm is rigidly clamped to the pin when the bolt is tightened.
One form of the invention has a single flat surface so that the boss forms a xe2x80x9cDxe2x80x9d shape, and a second form has two machined, parallel flat surfaces forming the boss that extends diametrically across the end of the pin. The non-circular surfaces can be planar, serrated, undulating or other suitable configurations. The mating opening in the retainer lever or arm is formed to fit over the boss.